Lecture 12 - Monday October 3, 2016
- Energy is mass, E=mc2
- The speed of light is so high, that a small amount of mass is equivalent to an
enormous amount of energy
- Combining two speeds less than the speed of light always results in a speed that is
al

Lecture 13 - Tuesday October 4, 2016
- What is light? Light behaves as a wave
- Speed:c, frequency:f, wavelength:
- speed=frequency*wavelength
c=f
- If is bigger, then f is smaller and vice versa
- Gamma rays can have 1023 waves per second (measured in Hz

Forces of Nature
The Fundamentals
Four Fundamental Forces of Nature
1 Strong force
Holds nuclei together
Operates only on very short ranges
Strength unit of 1
2 Electromagnetic force
Holds atoms together
Operates on an infinite range
Strength unit of 0.01

30) In relativity it says that if you are travelling at some constant speed then theres no way that you can
tell how fast you were moving if you did an experiment (it seems like we are still but we are never still
there is no still reference that is bett

1Lecture 2
General Notes
- if the Earth were as big as a basketball, the Moon would be as big as a tennis ball
- hierarchy:
1. planets
2. stars
3. galaxies
4. universe as a whole
- 1 million Earth's can pack inside the Sun
- 900 Jupiter's can pack inside

Lecture #1 (September 9th, 2015):
-
Planets, stars, galaxies (which is a collection of stars), and the universe as a whole are four broad
topics in a hierarchy of scales and sizes
o Although planets are the smallest of these four, there are things that ar

Lecture 14 - Thursday October 6, 2016
- Light emitted by a blackbody depends on: the temperature of an object. Material and
texture dont matter
- Particles going through a slit will land on a specific place on a wall on the other side
of the slit. If you

1
THE ATOM
All matter is made up of atoms. An atom is made up of two major
parts: First, there is a cloud of electrons (very light, negatively charged
particles filling most of the volume), and second, there is a central
nucleus, which is made up of a hea

Lecture 9 - Monday September 26, 2016
- The speed of light uses the symbol c
- Light moves about 1016 m in a year
- Gravity is one of the four basic forces of nature
- Galaxies are stable over time because gravity keeps it together balanced with the
motio

1. A black hole and a normal star have the same mass. They each have an Earth-sized planet orbiting
them at the same distance as the Earth is from the Sun. a) the planet is sucked into the black hole b) the
black hole pulls harder on its planet than the n